docs: def _handle_blacklisted_tag(self):
          """Handle the body of an HTML tag that is parser-blacklisted."""
          strip = lambda text: text.rstrip().lower()
          while True:
              this, next = self._read(), self._read(1)
              if this is self.END:
                  self._fail_route()
              elif this == "<" and next == "/":
                  self._head += 3
                  if self._read() != ">" or (strip(self._read(-1)) !=
                                             strip(self._stack[1].text)):
                      self._head -= 1
                      self._emit_text("</")
                      continue
                  self._emit(tokens.TagOpenClose())
                  self._emit_text(self._read(-1))
                  self._emit(tokens.TagCloseClose())
                  return self._pop()
              elif this == "&":
                  self._parse_entity()
              else:
                  self._emit_text(this)
              self._head += 1